The effect of three species of coccoid on guava seedlings and trees [electronic resource].
تأثير ثلاثة أنواع من فوق فصيلة كوكوئيديا على أشجار وشتلات الجوافة.
- p.1255-1267.
Includes reference.
Two experiments were carried out at El-Mansouria, Giza Govemorate during November 2005 till October 2Q06 to study some morphological, chemical composition and anatomical structure effects of infestation with Coccidge «Pulvinaria psidii Maskell (Homoptera: Coccidae), Hemiberlesia latanila (Signoret) (Homoptera: Diaspididae) and Icerya sychellarum (Westwood) (Homoptera: Margaarodidae» on seedling and trees. Results obtained could be summarized In the following: 1- The infestation-by H. I8tania and I. sychellarum caused a significant reduction in shoot length compared with uninfested seeldlings. while the infestation with P. psidi caused nonsignificant. Leaf area, leaf dry weight and ratio of nitrogen were leaves from guava seedling infested by H. Iatania, I. sychellarum and P. psldii have decrease significant effect compared with uninfested leaves. 2- Fruit quality of guava trees, fruit weight, juice volume, ascorbic acid and yield per tree were decrease for them, affected by Infestation by P. psidii, H. latania and I sychellarum 3- Histological measurements of different stems of Guava seedling infested by P. psidii and I. sychellarum compared with uninfested stems indicated that, there was a decrease in the diameter of whole $tem section. thickness of priderm, cortex and vascular cylinder. While the thickness of both internal phloem and cambium layers were increased. 4-Transverse sections of infested leaves by H. lataniae and I. sychellarum were show a decrease in thickness of midrib, lower cholenchymataus, diameter of midvein and blade, while the infested by P. psidii showed increase in midrib as a result of the increase in upper cholechyma and midvein.
Summary in Arabic.
Guava--Diseases and pests. Scale insects--Anatomy. Homoptera--Anatomy. Psidium guajava.