Improvement in Cassava Yield per Area by Fertilizer Application

Cassava is a source of carbohydrates to more than 200 million people in Sub-Saharan Africa, even though its production is 6–8 t ha−1, which is below the highest world production of 36.4 t ha−1 in India. To address this yield gap and increase cassava’s availability, affordability, and adequacy, intensive but sustainable production is important. Additionally, being an emerging raw material in the animal feeds, pharmaceutical, beer industries etc., only increases its demand, however the current production levels cannot effectively sustain this. Therefore, this paper reviews: improvement in cassava yields per area under fertigation and banding of fertilizers, a common practice among many farmers; the advantage of fertilizer application on starch of the storage roots, which is the fundamental ingredient in most industries using cassava as a raw material; and the climate smart technologies for intensive sustainable cassava production. In the end, this review enhances knowledge about fertilizer application to cassava, both banding and fertigation, and expounds on effective intensive sustainable climate-smart production strategies

Fruit load governs transpiration of olive trees

We tested the hypothesis that whole-tree water consumption of olives (Olea europaea L.) is fruit load-dependent and investigated the driving physiological mechanisms. Fruit load was manipulated in mature olives grown in weighing-drainage lysimeters. Fruit was thinned or entirely removed from trees at three separate stages of growth: early, mid and late in the season. Tree-scale transpiration, calculated from lysimeter water balance, was found to be a function of fruit load, canopy size and weather conditions. Fruit removal caused an immediate decline in water consumption, measured as whole-plant transpiration normalized to tree size, which persisted until the end of the season. The later the execution of fruit removal, the greater was the response. The amount of water transpired by a fruit-loaded tree was found to be roughly 30% greater than that of an equivalent low- or nonyielding tree. The tree-scale response to fruit was reflected in stem water potential but was not mirrored in leaf-scale physiological measurements of stomatal conductance or photosynthesis. Trees with low or no fruit load had higher vegetative growth rates. However, no significant difference was observed in the overall aboveground dry biomass among groups, when fruit was included. This case, where carbon sources and sinks were both not limiting, suggests that the role of fruit on water consumption involves signaling and alterations in hydraulic properties of vascular tissues and tree organs.</p

Effectiveness of bio-effectors on maize, wheat and tomato performance and phosphorus acquisition from greenhouse to field scales in Europe and Israel: a meta-analysis

Biostimulants (Bio-effectors, BEs) comprise plant growth-promoting microorganisms and active natural substances that promote plant nutrient-acquisition, stress resilience, growth, crop quality and yield. Unfortunately, the effectiveness of BEs, particularly under field conditions, appears highly variable and poorly quantified. Using random model meta-analyses tools, we summarize the effects of 107 BE treatments on the performance of major crops, mainly conducted within the EU-funded project BIOFECTOR with a focus on phosphorus (P) nutrition, over five years. Our analyses comprised 94 controlled pot and 47 field experiments under different geoclimatic conditions, with variable stress levels across European countries and Israel. The results show an average growth/yield increase by 9.3% (n=945), with substantial differences between crops (tomato > maize > wheat) and growth conditions (controlled nursery + field (Seed germination and nursery under controlled conditions and young plants transplanted to the field) > controlled > field). Average crop growth responses were independent of BE type, P fertilizer type, soil pH and plant-available soil P (water-P, Olsen-P or Calcium acetate lactate-P). BE effectiveness profited from manure and other organic fertilizers, increasing soil pH and presence of abiotic stresses (cold, drought/heat or salinity). Systematic meta-studies based on published literature commonly face the inherent problem of publication bias where the most suspected form is the selective publication of statistically significant results. In this meta-analysis, however, the results obtained from all experiments within the project are included. Therefore, it is free of publication bias. In contrast to reviews of published literature, our unique study design is based on a common standardized protocol which applies to all experiments conducted within the project to reduce sources of variability. Based on data of crop growth, yield and P acquisition, we conclude that application of BEs can save fertilizer resources in the future, but the efficiency of BE application depends on cropping systems and environments

Sulfate Fertilization Preserves Tomato Fruit Nutritional Quality

Sulfur is an essential mineral in human nutrition, involved in vital biochemical processes. Sulfur deficient soil is becoming a severe issue, resulting from increased agricultural production and decreased sulfur emissions. Tomato cultivation using sulfur-poor soils and desalinated water is becoming widespread, and might result in plant and fruit sulfur deficiency. In the current work, we aimed at evaluating the effect of sulfur fertilization (0.1–4 mM) on fruit sulfur concentrations, under both low (4 mM) and high (11 mM) nitrogen fertilization, to assess fruit sulfur biofortification, alongside the effect on fruit mineral composition, and on tomato plants. The experiment was performed on a semi-commercial scale, during two seasons, with a real-life fertilization range. We evaluated fruit elemental composition, in addition to young (diagnostic) leaves, as an indication to nutritional status. Our results show no harmful effect of low sulfur treatment on plant growth and high yield. Increased fertilization-sulfur exclusively induced sulfur accumulation in the fruit, while increasing fertilization-nitrogen subsequently increased fruit nitrogen. Sulfur treatments resulted in a consistent negative effect on fruit molybdenum and calcium, as well as a positive effect on fruit sodium levels. At the same time, other fruit minerals, including phosphorus, potassium, magnesium, iron, zinc, manganese, and copper, remained unaltered by sulfur treatments. Leaf response trends generally adhered to those of fruit. Taken together, our findings suggest that sulfur fertilization can biofortify tomato with sulfur while retaining fruit mineral composition and nutritional quality, excluding a decrease in Molybdenum levels, to assure food security and maintain fruit and vegetables as a significant source of sulfur and other minerals. Possibilities of practical application of this work’s results include optimization of fertilization levels in crop cultivation under sulfur deficiency for yield and nutritional quality, alongside the biofortification of tomatoes with sulfur and nitrogen with no adverse effect to other fruit minerals

Sulfate Fertilization Preserves Tomato Fruit Nutritional Quality

Sulfur is an essential mineral in human nutrition, involved in vital biochemical processes. Sulfur deficient soil is becoming a severe issue, resulting from increased agricultural production and decreased sulfur emissions. Tomato cultivation using sulfur-poor soils and desalinated water is becoming widespread, and might result in plant and fruit sulfur deficiency. In the current work, we aimed at evaluating the effect of sulfur fertilization (0.1&ndash;4 mM) on fruit sulfur concentrations, under both low (4 mM) and high (11 mM) nitrogen fertilization, to assess fruit sulfur biofortification, alongside the effect on fruit mineral composition, and on tomato plants. The experiment was performed on a semi-commercial scale, during two seasons, with a real-life fertilization range. We evaluated fruit elemental composition, in addition to young (diagnostic) leaves, as an indication to nutritional status. Our results show no harmful effect of low sulfur treatment on plant growth and high yield. Increased fertilization-sulfur exclusively induced sulfur accumulation in the fruit, while increasing fertilization-nitrogen subsequently increased fruit nitrogen. Sulfur treatments resulted in a consistent negative effect on fruit molybdenum and calcium, as well as a positive effect on fruit sodium levels. At the same time, other fruit minerals, including phosphorus, potassium, magnesium, iron, zinc, manganese, and copper, remained unaltered by sulfur treatments. Leaf response trends generally adhered to those of fruit. Taken together, our findings suggest that sulfur fertilization can biofortify tomato with sulfur while retaining fruit mineral composition and nutritional quality, excluding a decrease in Molybdenum levels, to assure food security and maintain fruit and vegetables as a significant source of sulfur and other minerals. Possibilities of practical application of this work&rsquo;s results include optimization of fertilization levels in crop cultivation under sulfur deficiency for yield and nutritional quality, alongside the biofortification of tomatoes with sulfur and nitrogen with no adverse effect to other fruit minerals

Effect of Mineral Nutrition and Salt Spray on Cucumber Downy Mildew (<i>Pseudoperonospora cubensis</i>)

It was previously shown that spraying with CaCl2, MgCl2, KCl, and K2SO4 and high N and Mg concentrations in the irrigation water of potted cucumber plants reduced powdery mildew, while medium P and high K concentrations increased powdery mildew. In the present work, we tested the effect of irrigation with N, P, K, Ca, and Mg and spraying with salts on downy mildew (Pseudoperonospora cubensis) of cucumber (CDM). In potted plants, an increase in N concentration in the irrigation water resulted in a major increase in CDM severity, while an increase in K or Ca concentrations resulted in a gradual increase in CDM severity. An increase in P and Mg concentrations in the irrigation water resulted in a major CDM decrease. Spraying with Ca, Mg, and K salts with Cl and SO4 anions resulted in CDM suppression in most cases, and a negative correlation was obtained between the salt and anion molar concentrations and the CDM severity. Using NaCl sprays, both Na and Cl concentrations were negatively related to the CDM severity. MgCl2 (0.1 M Cl), K2SO4 (0.1 M SO4), MgCl2 + K2SO4, and monopotassium phosphate (MKP, 1%) sprayed under commercial-like (CL) conditions significantly reduced CDM by 36.6% to 62.6% in one disease cycle, while, in a second cycle, CDM was significantly reduced only by K2SO4 and MKP. In conclusion, fertigation with P and Mg, and salt spraying decreased CDM, while only spraying under CL resulted in CDM suppression

Tef (Eragrostis tef) Responses to Phosphorus and Potassium Fertigation under Semi-Arid Mediterranean Climate

Tef (Eragrostis tef (Zucc.) Trotter) is an annual small grain, panicle bearing, C4 cereal crop native to Ethiopia, where it is a major staple food. The objectives of the present study were to characterize the responses of two tef genotypes to escalating phosphorus (P) and potassium (K) levels and to determine an optimum range for P and K at which tef performance is maximized. Two experiments were carried out in the Gilat Research Station, each testing two different genotypes of tef (405B and 406W), one experiment in pots in controlled conditions, and the other in the field. In both experiments, the highest grain yield increased until 6 mg L−1 P, and declined at 12 mg L−1 P. The decline was precipitous and significant in the pot experiment, and gradual and statistically insignificant in the field experiment. In the pots experiment, the grain yield increased until 40 mg L−1 K, with no significant decrease thereafter. The effect of K concentration was only seen in the grain yield and not in the size of the other plant organs. In the field experiment, grain yield was highest at 80 mg L−1 K, but it was not statistically different from 40 mg L−1. The effect of K on growth was only apparent at maturity and not at flowering

Effects of Microelements on Downy Mildew (Peronospora belbahrii) of Sweet Basil

We recently demonstrated that spraying or irrigating with Ca, Mg and K reduces the severity of sweet basil downy mildew (SBDM). Here, the effects of Mn, Zn, Cu and Fe on SBDM were tested in potted plants. The effects of Mn and Zn were also tested under semi-commercial and commercial-like field conditions. Spray applications of a mixture of EDTA-chelated microelements (i.e., Fe-EDTA, Mn-EDTA, Zn-EDTA, Cu-EDTA and Mo) reduces SBDM severity. The application of EDTA chelates of individual microelements (i.e., Fe-EDTA, Mn-EDTA and Zn-EDTA) significantly reduces SBDM in potted plants. Foliar applications of Mn-EDTA and Zn-EDTA are found to be effective under semi-commercial conditions and were, thus, further tested under commercial-like conditions. Under commercial-like conditions, foliar-applied Mn-EDTA and Zn-EDTA decreased SBDM severity by 46–71%. When applied through the irrigation solution, those two microelements reduce SBDM by more than 50%. Combining Mg with Mn-EDTA and Zn-EDTA in the irrigation solution does not provide any additional disease reduction. In the commercial-like field experiment, the microelement-mixture treatment, applied as a spray or via the irrigation solution, was combined with fungicides spray treatments. This combination provides synergistic disease control. The mode of action in this plant–pathogen system may involve features of altered host resistance