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The objective of the present study was to evaluate the performance (based on growth, yield, quality, and nutrient acquisition) of commercial greenhouse cucumber (Cucumis sativus) grafted onto different locally available species as rootstocks during winter. The performance of cucumber cv. Infinity as scion was tested onto selected genotypes of three species of genus Cucurbita (pumpkin, squash and figleaf gourd), one each of Lagenaria (bottle gourd) and Cucumis (muskmelon) used as rootstocks. Plant growth, fruit yield and quality characteristics, a n d n u t r i e n t a c q u i s i t i o n efficiency of rootstocks studied under prevailing sub-optimal temperatures during winter inside unheated greenhouse. The highest fruit yield was obtained in intergeneric cucumber grafting onto figleaf gourd followed by bottle gourd rootstocks, with increase in total yield of 30 and 10%, respectively over non-grafted cucumber. Fruit dry matter content in muskmelon grafted plants and titratable acidity in figleaf gourd and muskmelon grafted plants were also increased. The improved performance of cucumber onto t h e c u c u r b i t r o o t s t o c k s , especially figleaf gourd was related to the increased root dry mass, root/shoot ratio and rootstock-stem thickness. This was also associated with the enhanced leaf nutrient status provided by vigorous root system of figleaf gourd rootstock under prevailing sub-optimal temperature.

The performance of gynoecious cucumber (cv. Terminator) was evaluated under three protected structures viz., naturally ventilated polyhouse (NVP), insect proof net house (INH) and shade net house (SNH) at Jodhpur, Rajasthan in hot arid region of India. The photosynthetically active radiation (PAR) inside these structures during cropping period ranged from 154-842 μmol m-2 s-1 which was much lower than the outside. Among structures, air temperature was 1.2°C and 0.7°C lower while relative humidity (RH) was 17 and 4 per cent higher in NVP and SNH respectively as compared to INH. Relatively low air as well as soil temperature, coupled with high RH and optimal radiation in NVP led to better plant growth and physiological activity which resulted in 42 and 142per cent higher yield than INH and SNH, respectively. Hence, it can be recommended that NVP is the best low-tech protected structure which modifies the microclimate favouring successful cultivation of greenhouse cucumber in Indian hot arid regions.

Protected vegetable cultivation is a fast-growing sector in which grafting plays a crucial role for success. Cucumber is predominantly grown under protected conditions. The popular slicing (mini) cucumber comprises two segments, single- and cluster-fruit-bearing. In the present study, the performance of select fruit-bearing hybrids grafted as scions onto commercial Cucurbita hybrid rootstock ‘NS-55’ was evaluated under three different low-cost protected structures in arid regions. With respect to type of protected structure, cucumber performance was superior under a naturally ventilated polyhouse (NVP) than an insect net house (INH) or a shade net house (SNH). Micro-climate parameters inside NVP (air temperature, RH and PAR) were more congenial for cucumber than those in net houses, thereby facilitating improved physiology (chlorophyll fluorescence, chlorophyll and plant water potential) and leaf mineral status. Grafting invariably improved growth and yield parameters under all protected structures. Overall plant performance was better in the grafted cluster-fruit-bearing hybrid ‘Terminator’ than the single-fruit-bearing hybrid ‘Nefer’ or their non-grafted counterparts. Furthermore, NVP was found to be superior to net houses for water productivity, and grafted plants were more water use efficient than their counterpart non-grafted plants. Thus, NVP can be considered a suitable low-cost protected structure in conjunction with grafting to boost cucumber crop and water productivity in arid regions.