AGRICULTURAL RESEARCH COMMUNICATION CENTRE www.arccjournals.com/www.ijarjournal.com *Corresponding author’s e-mail: sudad.altaweel@coagri.uobaghdad.edu.iq 1 Horticulture Department, Floriculture Division, Agriculture Faculty, Damanhour Univ., Egypt. 2 Medical and Aromatic Plants Research Unit, Collage of Agriculture, Univ. of Baghdad., Iraq. 3 Pomology Department, National Research Centre, Giza, Egypt. 4 Fats and Oils Department, National Research Centre, Giza, Egypt. Indian J. Agric. Res., 52(5) 2018: 542-547 Print ISSN:0367-8245 / Online ISSN:0976-058X Effect of gibberellic acid and zinc sulphate on vegetative, flowering, seed yield and chemical consistent of jojoba plant (Simmondsia chinensis) A.K.G. Atteya 1 , S.K.Al - Taweel 2* , E.A.E. Genaidy 3 and H.A. Zahran 4 Horticulture Department, Floriculture Division, Agriculture Faculty, Damanhour Univ., EL-Behira-Egypt. Received: 10-03-2018 Accepted: 24-04-2018 DOI: 10.18805/IJARe.A-349 ABSTRACT This experiment was conducted to study jojoba response (Simmondsia chinensis) evergreen dioecious shrub to zinc sulphate plus gibberellic acid foliar application on vegetative, flowering, seed yield and seed chemical composition at private farm during two successive seasons of 2015 and 2016 in the Egypt. An experiment was laid out in randomized complete block design with three replications. In this study, jojoba plants were sprayed with all combination treatments of zinc sulphate (0, 25, 50 and 75ppm) plus gibberellic acid (0, 50, 100 and 150ppm) thrice in the beginning of December, March and May. There results revealed that all combination treatments showed a significant improvement in all examined parameters with an increase in ZnSO 4 / GA 3 levels in comparison with untreated trees. Therefore, the maximum significant branch length (99.36 and 103.46 cm), secondary branches length (55.82 and 58.36 cm) obtained by application of 75ppm ZnSO 4 plus 150ppm GA 3 treatment, so this combination recorded the highest percentage of flowering %, final fruit set (95.01, 95.24%), total chlorophyll, mineral% content, seed yield per feedan (2200, 2145 kg) and seed lipid content(57.6%, 58.55%) at first and second terms respectively. The application of 75ppm ZnSO4 plus 150ppm GA 3 treatment is recommended to improve jojoba traits which lead to raise its economic value as a promising tree which potentially useful as a biofuel with multi chemical and pharmaceuticals industries uses. Key words: Flowering, Gibberellic acid (GA 3 ), Jojoba, Seed chemical constituent, Seed yield, Zinc sulphate, INTRODUCTION Jojoba ( Simmondsia chinensis ) belongs to Simmondsiaceae family. Jojoba is a precious, drought resistant shrub, evergreen dioecious. It accumulates a unique storage lipid wax in its seeds consisting of long-chain esters of monounsaturated FA and alcohols (Gohil et al.,2010). Jojoba seed contains a high content liquid wax with a wide variety of applications as a biofuel and a pure natural product for cosmetic products and medical application as antioxidant, antimicrobial activities human burn actions effect, also used for multi-industrial-related products (Al- Obaidi et al.,2017). Jojoba plant appears to tolerant soil salinity and drought resistant, so jojoba can grow with a little water for survival (Abobatta, 2017). Swietlik, (2002) specified that Zinc applications on soil are not so effective since fruit crops roots occupy deeply in soil layers and zinc would not be easily removed from the soil. Zinc improves the biological machines, and these are consisting of proteins and enzymes (Stout, 1962). Since no studies has been done about the effect of zinc and gibberellic acid interaction on plant growth, flowering, seed yield in jojoba plants. The purpose of this research is to investigate the opportunity of improving the flowering, vegetative growth and seed yield as well as its oil yield and chemical consistent in jojoba plants by using gibberellic acid, zinc sulphate combination applied as a solution of foliar spray. MATERIALS AND METHODS This experiment was conducted to find out foliar application effect of zinc sulphate and gibberellic acid interaction on Jojoba tree traits at private farm in EL-Bahira governorate, Egypt. Jojoba similar age trees (nine years old) and size were nominated for sprays treatments in 2015 and 2016 seasons. The experiment laid out to a factorial arranged in randomized complete block design (RCBD) with three replications. For each treatment replication of same shoot was nominated. The orchard was irrigated by drip system, with weed and pest control, and fertilization conducted according to the standard agro-practices. The analysis of soil shown in Table 1, 2 and analysis of water irrigation is given in according to the certified procedures (Chapman and Pratt,1961). The zinc element plus GA 3 treatments were applied three times (at the beginning of December, March and May) in spread doses of 25, 50 and 75ppm. The gibberellic acid