Strategies to improve growth yield and fruit quality of ber (Ziziphus mauritiana L.) under arid conditions

Abstract

Food security, safety and quality are the burning issues of the time and there is need to explore new crops to fulfill the nutritional requirement. On the other hand, increasing concerns over increasing level of salinity has prompted researchers to evaluate resistant crops. Ber fruit known for its hardiness to grown on marginal lands of arid and semi-arid regions of the world is well appreciated for its taste, flavor and medicinal importance. Present studies are envisaged to evaluate the best strategies to improve growth, yield and fruit quality of ber orchards under arid and semi-arid conditions. Field studies were arranged in randomized complete block design while laboratory experiments in a completely randomized design with factorial arrangements. First experiment was conducted to evaluate the effect of brackish ground water. There were three treatments i.e. (NW) normal water, BW (brackish water 11 dsm-1) and NW + BW. These treatments were applied to four cultivars of ber (‘Delhi White’, ‘Mehmud Wali’ ‘Karela’ and ‘Suffan’). Data were collected on various growth parameters, leaf biochemical attributes, fruit physical and biochemical characteristics. The results of first experiment showed that application of BW significantly reduced the growth parameters, fruit physical parameters including yield. Biochemical attributes of leaves like chlorophyll along with potassium contents and TSS of fruits were also decreased with BW treatment; whereas, leaf proline contents, ascorbic acid, Na contents and TA were increased. In the 2nd experiment graft compatibility of four cultivars of ber was investigated on local rootstock. Parameters were collected on graft compatibility attributes and biochemical analysis. Ber cv. ‘Delhi White’ showed superior tree, leaves and fruits attributes compared with other cultivars. 2 Meanwhile, in 3rd experiment effect of nutrient application i.e. NPK, 0.3% ZnSO4 + NPK, 0.5% ZnSO4 + NPK and 0.7% ZnSO4 + NPK were applied on ber plants. Among different doses, the application of 0.5% ZnSO4 + NPK was found best with minimum days taken to flowering, with higher fruit setting %, fruit and flesh weight, fruit volume, fruit diameter and fruit yield plant-1 . Findings suggested that foliar spray of 0.5% ZnSO4 + NPK was the most optimum and increased in better yield and quality; meanwhile, ber cv. ‘Delhi White’ showed better response to the applied nutrition as compared with other cultivars of ber. On the other hand, position of fruit in tree canopy also plays important role in determining fruit quality. Therefore, 4th experiment of current study revolved around impact of canopy positions on quality of ber fruit. Fruits harvested from outer canopy showed superior edible quality with improved physicochemical characteristics; while, fruit macro (N, P, K) and micro nutrients (Ca, Mg, B, Zn, Cu) were higher in fruit harvested from under canopy position. In 5th experiment, all ber cultivars were evaluated for their storability at different temperature treatments (0oC, 4oC, 8oC and 12oC) and long term storage conditions (15, 30, 45 and 60 days). Results suggested that ber fruits stored at O oC and 4 oC exhibited better physicochemical fruit quality although TSS, TA, TSS: TA ratio, ascorbic acid contents and sugars were decreased continuously as storage period was prolonged. Among different ber cultivars cv. ‘Delhi White’ showed superior physico-chemical characteristics along with better storability at lower temperatures.