بررسی نقش علفهای هرز نهالستانهای صنوبر در نوسانات جمعیت آفات مهم آن در استان گیلان

Poplar is a one of the fast growing and prolific species that is used for forestation. Advising agro-technical methods with attention to ecological aspects is one of the effective and important factors in integrated management of pests. The object of this Investigation is studying the effects of different weeding treatments (complete weeding, monthly weeding & no weeding) on diametrical and vertical growth of poplar seedlings, evaluating variation of different weeding treatments and also identifying weeds of poplar nurseries and studying their effects on population densities of Chlorophanus votuptificus, slatymycterus marmoratus, stauronematus compressicornis and Paranthrene tabaniformis, that are Important pests of poplars in nurseries. This study was executed during the years 2001-2004 in Safrabasteh Research Station Located in Asteaneh Ashrafieh region of Guilan province. Cuttings of the clone, Populus deltoids 69/55, were planted in a randomized complete blocks design with 3 replications in the above mentioned station. Statistical analysis of the obtained data did not show any difference between the treatments in survival percentages of the seedlings. In other words, the three weeding treatments did not have a clear effect on survival of the seedlings. Diametric and vertical growth of healthy and infested seedlings to popular gall inducing moth was not affected by weeding treatments in the years 2001-2002. But in years 2003-2004, a significant difference was observed between different weeding treatments in diametric and vertical growth of seedlings (P<0.01). In fact different weeding treatments were effective on diameter and height of the seedlings in 2003 and 2004. The three weeding treatments had no significant effect on population densities of Chlorophanus votoptificus, stauronematus compressicornis and Paranthrene tabaniformis during the years 2001-2004 when the project was executed. No significant effect was observed in population of Platymycterus marmoratus in any of the years, but in 2004 density of this pest was different in various treatments and a significant difference was observed in P<0.01. The highest number of insects was in monthly weeding treatment and the least number was in weakly weeding treatment. As the nursery was effected by shadow of the nearby neighbor trees in the year 2001, effect of shadow on diametric and vertical growth of seedlings and population densities of some important pests were also evaluated. During the years that this project was executing, 236 Samples of weeds including 59 species from 49 genus and 23 families were collected in poplar nursery of Safrabasteh Research Station. Key words: Weeds, Pests, Paranthrene tabaniformis, Platymycterus marmoratus, Stauronematus compressicornis.

کلیدواژه ها:

صنوبر ، علف های هرز ، نهالستان ، آفات ، گیلان ، آستانه اشرفیه ، پروانه گالزای ، سرخرطومی برگ خوار ، زنبور برگخوار