Improvement of Pigeonpea in Eastern and Southern Africa Annual Research Planning Meeting 1994 21-23 Sep 1994

This publication is a report of the second Annual Research Planning Meeting of the ICRISAT/African Development Bank Pigeonpea Improvement Project. The 35 delegates included scientists and senior research administrators from nine countries in the southern and eastern Africa region (Kenya, Lesotho, Malawi, Namibia, Sudan, Swaziland, Tanzania, Uganda, and Zambia), and from ICRISAT. Progress made in collaborative pigeonpea research was reviewed at the Meeting, and detailed workplans and budgets formulated for research and extension work in each country for the 1994/95 crop season. The recommendations made at the Meeting stress several aspects, including the need for more rapid technology transfer, better availability of seed, regional nurseries for drought and wilt resistance screening, and more training programs, especially on pigeonpea utilization, in order to increase both local consumption and export

Farmer preferences and legume intensification for low nutrient environments

Improved varieties of legumes adapted to nutrient deficiency have the potential to improve food security for the poorest farmers. Tolerant varieties could be an inexpensive and biologically smart technology that improves soils while minimizing fertilizer costs. Yet other technologies that improve productivity and appear to be biologically sound have been rejected by farmers. To translate benefits to smallholder farmers, research on low-nutrient tolerant genes and crop improvement must keep farmer preferences and belief systems in the forefront. We review farmer participatory research on legume-intensification and soil fertility management options for smallholder farmers in Africa, including recent results from our work in Malawi and Kenya. We suggest that indeterminate, long-duration legumes are the best bet for producing high quality residues, compared to short-duration and determinate genotypes. This may be due to a long period of time to biologically fix nitrogen, acquire nutrients, photosynthesize and grain fill. Also, the indeterminate nature of long-duration varieties facilitates recovery from intermittent stresses such as drought or pest pressure. However, indeterminate growth habit is also associated with late maturity, moderate yield potential and high labour demand. These traits are not necessarily compatible with smallholder criteria for acceptable varieties. Malawi women farmers, for example, prioritized early maturity and low-labour requirement, as well as yield potential. To address complex farmer requirements, we suggest the purposeful combination of species with different growth habits; e.g. deep-rooted indeterminate long-duration pigeonpea interplanted with short-duration soyabean and groundnut varieties. On-farm trials in Malawi indicate that calorie production can be increased by 30% through pigeonpea-intensified systems. Farmers consistently indicate strong interest in these systems. In Kenya, a 55% yield increase was observed for a doubled-up pigeonpea system (a double row of pigeonpea intercropped with three maize rows) compared to traditional, low density intercrops. However, the need for improved pigeonpea varieties with high intercrop suitability, including reduced early branching, was highlighted by a farmer preference study in the same area. These examples illustrate the potential for participatory research methodologies to drive biophysical research in farmer-acceptable directions

Adaptation of spring-sown chickpea to the Mediterranean basin. I. Response to moisture supply

Chickpea is grown in spring as a rainfed crop in West Asia and North Africa (WANA) regions in areas with mean annual rainfall of not less than 400 mm but where the rainfall amount and distribution are highly variable. We hypothesized that for WANA, the best-adapted cultivars should produce high yields in years with low rainfall and be responsive to moisture supply in years with high rainfall. Studies were therefore conducted to determine whether there is genetic variability in response to moisture supply and if so, to develop breeding strategies that support our hypothesis. Chickpea cultivars of diverse origin were grown under a soil moisture gradient using a line-source sprinkler irrigation system at Tel Hadya, northern Syria during the 1986/87, 1987/88 and 1988/89 seasons. In 1986/87 rainfall (359 mm) was similar to the long-term average but temperatures in the March-May period were lower. In 1987/88 rainfall was high (504 mm); and in 1988/89, it was low (234 mm) and temperatures during the March-May period were higher than the long-term average. Rainfed mean grain yields were 0.984 t/ha in 1986/87; 1.099 t/ha in 1987/88 and 0.187 t/ha in 1988/89. Cultivars varied significantly in response of grain yield to moisture supply (3.93–9.29 kg/ha/mm in 1986/87; 2.15–8.19 kg/ha/mm in 1987/88; and 3.10–9.57 kg/ha/mm in 1988/89). Responsiveness to moisture supply (regression slope) was highly correlated with yield potential. However, the correlation between the responsiveness to moisture supply and drought (rainfed) yield was non-significant. Widely adapted (stable) cultivars (i.e. cultivars which are considered well adapted to variation in moisture supply) in 1986/87 and 1987/88 were those with high mean yield, high rainfed yields and high yield potential; and in 1988/89 when the rise in temperature in spring was fast, additional requirements for wide adaptation were early phenology and high harvest index. Chickpea cultivars with wide adaptation had deep root systems and high pre-dawn leaf water potential

Adaptation of spring-sown chickpea to the Mediterranean basin. II. Factors influencing yield under drought

Drought during the late vegetative and reproductive stages of development i the major constraint to the productivity of spring-sown chickpea in the rainfed farming systems of West Asia and North Africa. This paper examines the contribution of crop traits to yield under drought and determines the relative contributions of drought escape, yield potential and a drought response index (DRI) to such yield. In years with mild drought (1986/87 and 1987/88), high biomass, high yield potential and high harvest index were highly correlated with grain yield. During the severe drought of 1988/89, early flowering and low straw yield, high harvest index, yield potential, pod and seed number and seed mass were correlated with rainfed grain yield. Differences among chickpea cultivars in rainfed (drought) yield were partitioned into drought escape, yield potential and DRI. Drought escape accounted for 41% in 1986/87, 37% in 1987/88 and 69% in 1988/89; yield potential accounted for 47%, 37% and 1%, respectively; and DRI accounted for 4%, 17% and 17% of the variations, respectively. The three factors combined explained an average of 90% of the variability in grain yield. The DRI was used to quantify tolerance or susceptibility of a cultivar independently of drought escape (early flowering) and yield potential. Of the traits which were significantly associated with drought yield, high harvest index, large number of pod and high seed mass were associated with drought escape (early flowering), while deep root system, high leaf water potential at dawn and large number of seeds were associated with drought tolerance (DRI)

Improvement in Eastern and Southern Africa—Annual Research Planning Meeting 1993, 25-27 Oct 1993

The ICRISAT/African Development Bank (AfDB) Pigeonpea Improvement Project aims to develop and propagate the use of improved cultivars and management practices among pigeonpea farmers in eastern and southern Africa, and to increase the utilization of this crop in both regions. This publication is a report of the Annual Research Planning Meeting 1993, held at Bulawayo, Zimbabwe, 25-27 Oct 1993 and attended by ICRISAT scientists, AfDB representatives, and NARS scientists from 11 countries. Research progress made since the project was launched is reviewed; the major production/utilization constraints in each country, and ways to alleviate them, are discussed; and workplans (detailing proposed activities, methodologies, budgets, etc.) are presented for collaborative pigeonpea research in eastern and southern Africa

Utilization of landraces for the genetic enhancement of pigeonpea in eastern and southern Africa

The eastern and southern Africa (ESA) region is considered as a centre of secondary diversity for pigeonpea. Accessions (297) of pigeonpea landraces were collected from major production areas in four countries in the region and evaluated for desirable agronomic traits, particularly resistance to fusarium wilt and market-preferred traits. Selected germplasm was utilized in the regional breeding program aimed at genetic enhancement of pigeonpea. Five improved long-duration (LD) cultivars that are highly resistant to fusarium wilt and have large (100-grain weight >15.0 g) grains were developed. Similarly, six early maturing medium-duration (MD) cultivars (averaging 2.5 t/ha) for production in the high latitude areas in the region and three MD cultivars that are able to ratoon, were developed. Seed of pre-released cultivars that are preferred by the farmers was distributed widely in the region in order to facilitate adoption. Consequently, the productivity of pigeonpea and food security in the region improved significantly

Yield and Water Use Efficiency of Faba Bean Sown at Two Row Spacings and Seed Densities

The performance of promising genotypes of faba bean developed for areas with limited rainfall was compared with the local landrace, ILB 1814, at Tel Hadya in Syria during 1989–1988 using different row spacings and sowing densities. In the last two years of the trials the performance of the improved genotypes and ILB 1814 was compared with and without supplemental irrigation. Yields of ILB 1814 were better than the highest yielding genotypes in some years and similar to them in others. In seasons with limited rainfall the best yields were obtained by using a narrow row spacing and dense sowing, and yields were significantly improved by irrigation. Grain yield was correlated with biomass and the number of pods per unit area. The percentage of radiation intercepted was highest in ILB 1814, particularly when sown with a narrow row spacing and at a high plant density. Soil water extraction, evapotranspiration and water use efficiency were improved by sowing at a narrowrow spacing and high plant density

The response of short-duration pigeonpea lines to variation in temperature under field conditions in Kenya

Field studies with pigeonpea (Cajanus cajan (L.) Millsp.) were conducted at four locations in Kenya varying in altitude and where temperature decreased with increase in altitude. Warm temperatures (most inductive temperatures, mean 23.5°C) hastened the times from sowing to flowering (f) and maturity (m), and between flowering and maturity (fm). Cool temperatures (17.8°C) delayed f, m, and fm but the delay was most pronounced for fm. In the least inductive cool environment, variation in f, m and fm was greatest among 63 lines developed in India. Compared to the most inductive temperature, the delay in cool environment was 2.2 for f, 3.1 for m, and 5.5 for fm, which indicates that fm is the most sensitive phase to low (sub-optimal) temperatures. Equations that describe the rates of development (1/f, 1/m, and 1/fm) were used to determine progress to different stages of development. Results revealed that optimum temperature for fastest time to flowering varied from 23.1 to 26.1°C. The 1/f at mean temperature of 26.8°C was slower, indicating that the mean temperature experienced was supra-optimal. Since the mean temperature of 26.8°C was not very different from the range considered optimal, further analysis revealed that this was mainly due to the high night temperatures. The 1/fm was strong and positive in the range of temperature tested indicating that warm temperatures shortened the duration between flowering and maturity. The optimum temperature range for this effect varied from 24 to 32°C. Cool temperatures at Kabete retarded plant growth while warm temperatures enhanced i

Some aspects of pod characteristics predisposing pigeonpea (Cajanus cajan (L.) Millsp.) to infestation by Callosobruchus chinensis (L.)

Investigations with pigeonpea (Cajanus cajan) genotypes ‘Apio-elina’ and ‘PI-397566’ showed that certain pod characteristics influenced both infestation in the field by Callosobruchus chinensis and damage caused by this pest. Compared to pods with no or sparse hair, pods with thick hairs suffered greatly reduced field infestation due to the barrier effect of the hairs on oviposition and larval penetration. Even on pods with no or few hairs, the pod wall appeared to offer some resistance to both larval penetration and adult emergence. High levels of infestation by C. chinensis were recorded on pigeonpea pods with no or few hairs, those with pods damaged through shattering, and those with pods that had been previously damaged by pod borers. From the results of the study, it was recommended that pigeonpea selection should include screening for high pod hair density and thicker pod wall

Inheritance of fusarium wilt resistance in pigeonpea [Cajanus cajan (L.) Millspaugh]

Fusarium wilt caused by Fusarium udum Butler is the most important disease of pigeonpea worldwide. Objectives of this study were to determine the mode of genetic inheritance of Fusarium wilt resistance in different pigeonpea accessions and to determine different genes governing resistance that exists in pigeonpea accessions. F1, F2 and backcross populations were developed by crossing resistant accessions (ICEAP 00554, ICEAP 00557) with susceptible accessions (KAT 60/8, ICP 7035). The Parents, F1, F2, backcrosses (BC1F1 and BC2F1) populations were evaluated for Fusarium wilt resistance. F2 populations derived from ICEAP 00554 × KAT 60/8, ICEAP 00557 × KAT 60/8, ICEAP 00554 × ICP 7035, ICEAP 00557 × ICP 7035 crosses exhibited a 3:1 ratio which indicated that resistance to Fusarium wilt was under the control of major gene, however, a recessive gene was detected from ICP 7035 × KAT 60/8 cross. The genes detected could be valuable for wilt resistance breeding