Limitations to seed yield in short-duration pigeonpea under water stress

Abstract

Yield components were deterininrd for two short-durat~on pigeonpea [Cujanu.i c.crjan (L. I Millsp. cult~vars, ICPL 87 and ICPL. 1.5 1 , In re\ponse to termtnal drought \Ires\ with three partla1 flowrrlpod removal or four foliar fert~ll/atlon treatments applied from the time or lull flowering. Flower/pod removal treatments compr~\ed a control w~t h no flowerlpod removal, lowerplant flower and pod removal at full flowrnng and 18 days later (EL), allowing pods to develop only on the top-3 nodes of the maln stem. and floweripod removal I X days after full flowering only (Li The EL and L treatments were applied to lCPL 87 and t)nl> the EL treatment 10 ICPL 15 1. Seed y~r l d of the top-3 nodes was tncreared by the EL treatment for hoth cult~vars under r a~n k d and irr~gnted condtt~ons, hut was not significantly affected hy the L treatment. With Hc>wer/ptd removal. Increased yielda of the top-3 nodrs were due to increases in the ptd density andlor the seed \ile, wlth little change In the numher of seeds pod ' Foliar l'enil17at1on of cultivar ICPL 87 with solutions containing N, P, K and S In \imilarproport~ons to those hund in developtng \eed\ at 20 and 40 kg N ha '. had no significant effects on yield or yield components under either soil moisture condition. Factors within the plant durlnp early reproductive growth appear to limit seed yield under both soil moisture cond~tions, and repro duct^! e sink capacity and nutrient (N. P. K and S 1 supply, apparently. are not limiting. Such information on plant factors l~m r t~n g yield under water stre\\ condittons allows for a better understandtng ot drought resistance mechanism(\) for shonduration plgeonpea.

Effects of Timing of Drought Stress on Phenology, Yield and Yield Components of Short‐duration Pigeonpea

“…Genotypes are arranged in order of increasing time to flowering, their growth habits are as indicated in Table 1 Drought Stress and Phenology in Pigeonpea , 1985). Terminal water stress beginning from flowering reduces the time to maturity for two short-duration pigeonpea genotypes (ICPL 87 and ICPL 151;LoPEZ et al 1994), which were also included in the present study. Thus, a more prolonged or severe water stress period than the one in the present study can reduce the duration of reproductive growth in these genotypes.…”

“…In pigeonpea, the number of seeds pod" appears to be the most stable yield component under water stress (KEATINGE and HUGHES, 1981). When two short-duration pigeonpea genotypes are subjected to terminal water stress and partial removal of flowers and pods, the number of seeds pod"^ is relatively unchanged ^ompared to changes in the number of pods m -and 100-seed mass (LOPEZ et al 1994). In soybean, 100-seed mass is more stable under water stress for determinate compared to indeterminate genotypes (KADHEM et al 1985b), however, no such differences were observed for short-duration pigeonpea in the present study.…”

“…For improvement in the stability of pods m~ , the high stability of the other yield components should be more fully exploited. Production of large pod walls with many seeds pod may exacerbate intra-plant competition for available plant factors at the time of pod set, which can possibly limit seed yield of short-duration pigeonpea under water stress conditions (LoPEZ et al 1994). Many small pods with fewer but larger seeds may help transfer some of the intra-plant competition among reproductive units to later growth stages because of the lower initial requirements of each expanding pod.…”

Effects of Timing of Drought Stress on Abscission and Dry Matter Partitioning of Short‐duration Pigeonpea

“…The contribution of pods (length > 20 mm) to the dry mass of fallen plant material was small and not significandy affected by any of the water stress treatments for all genotypes. Yield of short-duration pigeonpea under both rainfed and irrigated conditions is greatly affected by internal plant conditions existing at the time of pod set and early pod development (LOPEZ et al, 1994). In addition, the only yield component that decreases significantly under water stress is the number of pods m~~ (LOPEZ et al, 1996), suggesting that the degree of yield stabilit)^ under water stress conditions is detemiined largely during pod set and early pod development.…”

Biomass and nitrogen traits of summer pigeon peas and winter wheat grown for three rotations in containers

“…In other parts of the world, research has shown that the use of specific cultivars and (Brady)Rhizobium strains may optimize yield (8,9) and N 2 -fixation (10,11) of pigeon pea. One of the first steps in evaluating the benefits of pigeon pea, therefore, is to determine whether or not similar variation exists in the performance of cultivars and inoculum strains fit for this region.…”