Effect of Soil Salinity on Physiological Traits of two Butternut Squash (Cucurbita Moschata L. Mellonia) Varieties in Mwea, Kenya

Author(s): Nyambura M, Gathaara M, Menge D, Wanjogu R

Kenyan soils are greatly affected by high salt levels which has caused a decline in crop yields. Eighty percent of Kenya’s land is in ACZ V and VI that are prone to salinity. Farmers in these arid and semi-arid areas are adopting growth of non-staple food with butternut squash being one of them. Despite its economic potential, little research has been carried out on butternut squash and information on its physiological response to salinity is scarce. This study was therefore carried out to investigate the physiological response of Waltham butternut (Waltham) and Jupiter F1 hybrid (Jupiter) to salinity. The two butternut varieties were subjected to five NaCl concentrations i.e. 0, 25, 50, 75 and 100 mM resulting in ten treatments. These were arranged in a randomized complete block design with three replicates. A net plot was established from which the following data were recorded; transpiration rate, photosynthetic rate, stomatal conductance and chlorophyll concentration. The data were subjected to Analysis of variance (ANOVA) and means were separated using least significant difference (LSD) at 5 percent level. Transpiration rate, photosynthetic rate, stomatal conductance and chlorophyll concentration significantly decreased with an increase in salinity in Waltham and Jupiter. Adverse effects of salt were noted more on salinity level above 75 mMNaCl. However, the effects were low on Jupiter compared to Waltham implying it is more salt tolerant. Farmers in areas whose soils are saline are therefore recommended to adopt growing Jupiter F1 hybrid which showed tolerance to higher levels of salts and also maintain salinity levels below 75 mMNaCl to ensure maximum performance of the plants hence yield.