Yield and physiological responses of mungbean Vigna radita (L.) Wilczek genotypes to high temperature at reproductive stage

A study was conducted to examine the physiological responses and yield of contrasting mungbean genotypes viz, MH 421, MH 318 and Basanti differing in their sensitivity to high temperature raised in earthen pots (30 cm diameter) filled with 5.5 kg of dune sand (Typic Torrispamments) under screen house conditions. High temperature stress was given by manipulating sowing dates i.e. normal (12th March, 2013) and late (29th March, 2013) sown. Samplings were done at 3 and 7 days after exposure (DAE) of temperature above 35°C at reproductive stage. Sampling below 35°C temperature was considered as control. High temperature resulted in decreased chlorophyll stability index, chlorophyll and carotenoid contents, relative stress injury and yield. Sensitive genotypes showed large reductions in aforementioned physiological traits. On the other hand, tolerant genotype (MH 421) maintained higher chlorophyll stability index, chlorophyll and carotenoid contents, relative stress injury and yield. After 7 days of exposure to high temperature under late sown, A significant decrease was noticed in genotypes MH 318 and Basanti.

EFFECT OF DEFICIT IRRIGATION ON YIELD, RELATIVE LEAF WATER CONTENT, LEAF PROLINE ACCUMULATION AND CHLOROPHYLL STABILITY INDEX OF COTTON–MAIZE CROPPING SEQUENCE

SUMMARYWater stress induces some physiological changes in plants and has cumulative effects on crop growth and yield. Field experiments were conducted to study the effect of deficit irrigation (DI) on yield and some physiological parameters in cotton and maize in a sequential cropping system. Creation of soil moisture gradient is indispensable to explore the beneficial effects of partial root zone drying (PRD) irrigation and it could be possible only through alternate deficit irrigation (ADI) practice in paired row system of drip layout that is commonly practiced in India. In the present study, PRD and DI concepts (creation of soil moisture gradient) were implemented through ADI at two levels of irrigation using drip system. Maize was sown after cotton under no till condition without disturbing the raised bed and drip layout. Relative leaf water content (RLWC) and chlorophyll stability index (CSI) of cotton and maize were reduced under water stress. A higher level of leaf proline content was observed under severe water-stressed treatments in cotton and maize. RLWC and CSI were highest and leaf proline content was lowest in mild water deficit (ADI at 100% crop evapotranspiration once in three days) irrigation in cotton and maize. The same treatments registered higher values for crop yields, net income and benefit cost ratio for both the crops.