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Objectives: The indigenous oilseed crops are facing the problems of insects, diseases attack with poor yield potential. Canola needs high water requirement and also > 50 % shattering losses. Therefore, farmers are compelled to cultivate alternative crops. Sinapis alba is the best replacement of winter rapeseed due to superior phenotypic plasticity for dry temperate climate like Pakistan Pertinent sowing time augments the soil and climatic resources efficiency in a specific ecological zone to expose various phenological stages for appropriate growth and development to achieve potential yield. Methods: Field experiments were performed to appraise the suitable sowing date at three locations (NARC, SAWCRI and Talagang) in Pothwar plateau of Pakistan. Six sowing dates from 1st October up to 15th December with fifteen days interval were quart replicated in RCBD during two 2017–18 and 2018–19. Explicated environment of various locations prudently influenced Sinapis alba performance and yield attributes to accomplish potential yield during both years. Among sowing dates, 15th October enormously promoted morphological development to attained maximum mean values of pods plant−1, 1000-seed weight, biological yield and seed yield. Among locations, SAWCRI nurtured highest number of plants−2, plant height, primary and secondary branches, pods plant−1, seed pod-1, 1000-seed weight, biological yield and seed yield. Variability in Agro-meteorological indices of three locations significantly influenced the interactive effect of year × location × sowing dates for growth and yield attributes of Sinapis alba. It was observed that 15th October sowing at SAWCRI attained 2.25 t ha−1 seed yield that was 10.9 % and 24.4 % higher from the optimal dates at NARC and Talagang that accomplished 84.43 %. 91.12 % and 95.76 % more yield from the delayed (15th Dec) sowing at three locations. Conclusion: Better coordination of soil and climatic conditions with 15th October sowing for growth and development signified the monumental importance of optimal sowing date as the benchmark of superior crop productivity to improve the livelihood of the farmers.

Effects of water-deficit stress and foliar-applied gibberellic acid (GA3) on ‘Washington’ navel orange (Citrus sinensis) floral gene expression and inflorescence number were quantified. Trees subjected to 8 weeks of water-deficit stress [average stem water potential (SWP) −2.86 MPa] followed by 3 weeks of re-irrigation (SWP recovered to > −1.00 MPa) produced more inflorescences in week 11 than trees well-irrigated (SWP > −1.00 MPa) for the full 11 weeks (P < 0.001). After 8 weeks of water-deficit stress, bud expression of flowering locus t (FT), suppressor of overexpression of constans1 (SOC1), leafy (LFY), apetala1 (AP1), apetala2 (AP2), sepallata1 (SEP1), pistillata (PI), and agamous (AG) increased during the re-irrigation period (weeks 9 and 10), but only AP1, AP2, SEP1, PI, and AG expression increased to levels significantly greater than that of well-irrigated trees. Foliar-applied GA3 (50 mg·L−1) in weeks 2 through 8 of the water-deficit stress treatment did not reduce bud FT, SOC1, or LFY expression, but prevented the upregulation AP1, AP2, SEP1, PI, and AG expression that occurred during re-irrigation in water-deficit stressed trees not treated with GA3. Applications of GA3 to water-deficit stressed trees reduced inflorescence number 95% compared with stressed trees without GA3. Thus, GA3 inhibited citrus (Citrus sp.) floral development in response to water-deficit stress through downregulating AP1 and AP2 expression, which likely led to the failed activation of the downstream floral organ identity genes. The results reported herein suggest that bud determinacy and subsequent floral development in response to water-deficit stress in ‘Washington’ navel orange are controlled by AP1 and AP2 transcript levels, which regulate downstream floral organ identity gene activity and the effect of GA3 on citrus flower formation. The water-deficit stress floral-induction pathway provides an alternative to low-temperature induction that increases the potential for successful flowering in citrus trees grown in areas experiencing warmer, drier winters due to global climate change.