Response of pigeonpea genotypes of differrent maturity duration to temperature and photoperiod in Kenya

Pigeonpea (Cajanus cajan (L.) Millsp.) is one of the major grain legumes grown in the tropics and subtropics. The crop is grown rainfed in prone drought areas where day length varies from 11 to 14 h and large differences in temperature are experienced, largely due to variations in altitude and latitude. Field studies were conducted with different pigeonpea [Cajanus cajan (L.) Millsp.] in Kenya to determine the effect of photoperiod and temperature on flowering. Variation in temperature was achieved by planting six genotypes at four locations varying inaltitude where temperature decreased with increase in altitude and variation in photoperiod was achieved through artificial lighting (about 12.6 hr - natural day length, 14.5 hr and 16.0 hr). The genotypes used in the study were carefully selected to represent different maturity duration (extra-short-, short-, medium- and long maturityduration) and major piegonpea production regions. Equations that describe the rates of development (1/f) were used to determine rates of progress of each genotype towards flowering as influenced by temperature and photoperiod. For photoperiods below 13 hr, rates of progress towards flowering were influenced by temperaturein give genotypes (ICPL 90011, ICPL 87091, ICP 7035, ICP 6927 and ICEAP 00040). The optimum temperature for rapid flowering were 24.7 oC for the extra-short-duration genotype, 23.1 oC for the shortduration genotye, 23.8 and 22.2 oC for medium-duration genotypes and 18.3 oC for the long-duration genotypes,22.2 oC for medium-duration genotypoes and 18.3 oC for the long-duration genotypes which indicated that the area of origin had a strong influence on adaptation. The effects of photoperiod on rates of progress towards flowering were investigated only under sub-optimal temperatures. The extra-short-duration genotype (ICPL 90011) was the least responsive to variation in photoperiod, while the two long duration genotypes (ICEAP 00040 and T-7) were to most sensitive to photoperiod variation with flowering rate reduced by 0.001 d-1 per hourincrease in day length

Response of pigeonpea genotypes of different maturity duration to temperature and photoperiod in Kenya

Pigeon pea (Cajanus cajan) is one of the major grain legumes grown in the tropics and subtropics. The crop is grown rainfed in prone drought areas where daylength varies from 11 to 14 h and large differences in temperature are experienced, largely due to variations in altitude and latitude. Field studies were conducted with different pigeon pea in Kenya to determine the effect of photoperiod and temperature on flowering. Variation in temperature was achieved by planting six genotypes at four locations varying in altitude where temperature decreased with increasing altitude, and variation in photoperiod was achieved through artificial lighting (approximately 12.6 h, natural daylength, 14.5 h and 16.0 h). The genotypes used were carefully selected to represent different maturity duration (extra-short-, short-, medium- and long-maturity durations) and major pigeon pea production regions. Equations that describe the rates of development (1/f) were used to determine rates of progress of each genotype towards flowering as influenced by temperature and photoperiod. For photoperiods below 13 h, rates of progress towards flowering were influenced by temperature in five genotypes (ICPL 90011, ICPL 87091, ICP 7035, ICP 6927 and ICEAP 00040). The optimum temperature for rapid flowering were 24.7°C for the extra-short-duration genotype, 23.1°C for the short-duration genotype, 23.8 and 22.2°C for medium-duration genotypes and 18.3°C for the long-duration genotypes, 22.2°C for medium-duration genotypes and 18.3°C for the long-duration genotypes which indicated that the area of origin had a strong influence on adaptation. The effects of photoperiod on the rates of progress towards flowering were investigated only under sub-optimal temperatures. The extra-short-duration genotype (ICPL 90011) was the least responsive to variation in photoperiod, while the two long-duration genotypes (ICEAP 00040 and T-7) were the most sensitive to photoperiod variation with flowering rate reduced by 0.001 d-1 per hour increase in daylength

Response of Pigeonpea Genotypes of Different Maturity Duration to Temperature and Photoperiod in Kenya

Pigeonpea ( Cajanus cajan (L.) Millsp.) is one of the major grain legumes grown in the tropics and subtropics. The crop is grown rainfed in prone drought areas where day length varies from 11 to 14 h and large differences in temperature are experienced, largely due to variations in altitude and latitude. Field studies were conducted with different pigeonpea [Cajanus cajan (L.) Millsp.] in Kenya to determine the effect of photoperiod and temperature on flowering. Variation in temperature was achieved by planting six genotypes at four locations varying in altitude where temperature decreased with increase in altitude and variation in photoperiod was achieved through artificial lighting (about 12.6 hr - natural day length, 14.5 hr and 16.0 hr). The genotypes used in the study were carefully selected to represent different maturity duration (extra-short-, short-, medium- and long maturity duration) and major piegonpea production regions. Equations that describe the rates of development (1/f) were used to determine rates of progress of each genotype towards flowering as influenced by temperature and photoperiod. For photoperiods below 13 hr, rates of progress towards flowering were influenced by temperature in give genotypes (ICPL 90011, ICPL 87091, ICP 7035, ICP 6927 and ICEAP 00040). The optimum temperature for rapid flowering were 24.7 °C for the extra-short-duration genotype, 23.1 °C for the shortduration genotye, 23.8 and 22.2 °C for medium-duration genotypes and 18.3 °C for the long-duration genotypes, 22.2 °C for medium-duration genotypoes and 18.3 oC for the long-duration genotypes which indicated that the area of origin had a strong influence on adaptation. The effects of photoperiod on rates of progress towards flowering were investigated only under sub-optimal temperatures. The extra-short-duration genotype (ICPL 90011) was the least responsive to variation in photoperiod, while the two long duration genotypes (ICEAP 00040 and T-7) were to most sensitive to photoperiod variation with flowering rate reduced by 0.001 d-1 per hour increase in day length.Le pois pigeon ( Cajanus cajan (L.) Millsp) est une des principales légumes plantées dans les régions tropicales et subtropicales. La culture est alimentée par les pluies pour sa croissance dans les zones susceptibles de sécheresse, au sein desquelles la durée de la journée varie de 11à 14h et des grandes différences de température sont observées, en majorité dues aux variations d'altitude et de latitude. Des études de terrain étaient conduites avec différents types de pois pigeon [Cajanus cajan (L.) Millsp.] au Kenya en vue de pouvoir déterminer l'effet de la photopériode et de la température sur la floraison. Les variations de température étaient réalisées au moyen de six génotypes plantés dans quatre endroits d'attitude différentes où la température baissait en fonction d'un accroissement en attitude tandis que la variation de photopériode était atteinte par éclairage artificiel (Environ 12,6 hr - longueur de journée naturelle, 14, 5hr et 16, 0hr). Les génotypes utilisés au cours de l'étude étaient attentivement choisis en vue de pouvoir représenter des durées de maturité variables (extra-courte, courte, moyenne et longue) ainsi que les principales régions productrices de pois pigeon. Des équations décrivant le taux de développement (1/f) étaient utilisées dans le but de déterminer le taux de progression de chaque génotype vers la floraison tel qu'influencé par la température et la photopériode. Pour des photopériodes ne dépassant pas 13 hr, ces taux étaient influencés par la température dans des génotypes donnés (ICPL 90011, ICPL 87091, ICP 7035, ICP 6927 et ICEAP 00040). La température optimale pour une croissance rapide étaient de 24.7°C pour le génotype à durée extra-courte, 23,1°C pour celui à durée courte, 23,8°C et 22,2°C pour le génotype à durée moyenne et enfin 18,3°C pour celui à longue durée; ce qui montrait que la région d'origine présentait une forte influence sur l'adaptation. Les effets de la photopériode sur le taux de progrès vers la floraison étaient recherchés seulement sous températures sub-optimales. Le génotype à durée extra-courte (ICPL 90011) était le plus réceptif quant aux variations de photopériode, pendant que les 2 génotypes à durée longue (ICEAP 00040 et T-T) étaient les plus réceptifs à la variation de la photopériode, avec des taux de floraison réduits de 0.0001 d-1 par heure d'augmentation en longueur de journé