The current study was conducted to evaluate the effects of indole-3-butyric acid (IBA) at 100 ppm with or without biostimulants (Agrobacterium rhizogenes, seaweed extract and coconut water) as either a spray or drench for 3 minutes or 1 hour on rooting and growth parameters of three cutting types (tip, middle and basal) of Conocarpus erectus L. The data showed that the rooting percentage, root and vegetative characteristics of rooted cuttings were significantly increased by all treatments of IBA and/or biostimulants compared to the untreated cuttings. The individual treatments of seaweed extract and coconut water were more effective than IBA or A. rhizogenes alone. Seaweed extract as drench with or without IBA surpassed those of seaweed extract treatments as spray. Besides, the response of cuttings treated with coconut water for 1 hour was better than coconut water for 3 min. Tip cuttings were significantly better than the middle and basal ones, especially in relation to rootability of cuttings. Maximum rooting percentage and shoot characteristics of plants were obtained from tip cuttings treated with IBA + coconut water for 1 hour, followed by IBA + seaweed extract as drench. The highest rooting percentage was associated with high endogenous levels of phenols, indole acetic acid (IAA) and gibberellic acid (GA) as well as the lowest abscisic acid (ABA) level in cutting tissues and the anatomical structure of rooted cuttings. So, it can be recommended treating tip cuttings of C. erectus with either coconut water for 1 hour or seaweed extract as drench combined with IBA for enhancing the rooting percentage, root and shoot growth parameters as well as content of endogenous root promoting substances.

The black vine thrips, Retithrips syriacus Mayet (Thripidae: Thysanoptera) and the European red mite, Panonychus ulmi Koch (Tetranychidae: Prostigmata) cause serious damage to grapevine. Biotic and abiotic factors can be either helpful or harmful to pest's population, and understanding of such factors may contribute to better pest control. This study aimed at investigating the effect of the two predators (Scolothrips longicornis and Amblyseius hutu), temperature and relative humidity (RH) on the population fluctuations of these two pests on Muscat, Thompson seedling and Azmerly grapevine cultivars during the 2007/2008 and 2008/2009 growing seasons. The results indicated that R. syriacus fluctuated throughout the two seasons. The peak was recorded during June (2007/2008) and September (2008/2009) on the three grapevine cultivars.Although, the population fluctuation of P. ulmi differed during the two studied seasons, but the peak was recorded during May or June in both seasons according to the grapevine cultivars. In both growing seasons, it seems that both pests have one generation a year, and high temperature and moderate RH seem to be favorable for both pests. During both growing seasons, the population of both predators reached a peak in May and June on the three cultivars. Minimum temperature and RH played an important role in regulating the population changes of R. syriacus and P. ulmi, respectively. Mean numbers of the two associated predators, Scolothrips longicornis and Amblyseius hutu were significantly higher in 2007/2008 than 2008/2009 on Muscat and Thompson seedling. There was a negative significant correlation between the populations of both predators and R. syriacus and P. ulmi. In conclusion, the selected abiotic and biotic factors played the most important role in regulating the population density of these two pests.

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