INCREASING PRODUCTIVITY OF HEAD LETTUCE BY FOLIAR SPRAYING OF SOME BIO AND ORGANIC COMPOUNDS

Two field experiments were conducted during the two successive winter seasons of 2004/2005 and 2005/2006 at Berkash cv. Lymor (9283) to foliar spray by dry yeast at a rate of ( 2 and 4 g/L), amino green compound at a rate of (2 and 4 ml/L) and humic acid at a rate of (2 and 4 ml/L) on growth, yield and s"Giza Governorate" to investigate the response of head lettuce plants ome chemical contents of head lettuce plants.The results indicated that, application of amino green compound as a foliar spray at a rate of 4 ml/L gave the maximum number of head lettuce leaves compared with other treatments. In addition, the highest values of leaf dry weight, head fresh weight, total yield of heads and quality ( ascorbic acid and T.S.S ) were obtained by foliar application of 4 g/L dry yeast.The lowest amount of N-NO3 in leaves of head lettuce was recorded by using humic acid as a foliar spray at a rate of 4 ml/L. On the other hand, the highest amount of N-NO3 was recorded when amino green compound was used as a foliar spray at a rate of 4 gm/L. The highest content of N and P as well as Fe, Mn and Zn were recorded by foliar spray of dry yeast at a rate of 4 ml/L. Meanwhile, the highest amount of K given when humic acid was sprayed at a rate of 4 ml/L. INTRODUCTION Head lettuce (Lactuca sativa L.) is the world's most used salad crop. It is one of the important leafy vegetable crops which are eaten fresh and is a major and extensively grown cool season vegetable best adopted to temperate locations (Rubatzky and Tamaguchi, 1997). Dry yeast is a natural bio-substance suggested to be of useful stimulatory, nutritional and protective functions when it is applied on to vegetable plants during stress conditions due to its content of hormones, sugars, amino and nucleic acids, vitamins and minerals. Thereby, it can be induce thermatolerance due to its role in the synthesis of protein and nucleic acids and in minimizing their degradation (Natio et a.l, 1981). Many investigations cleared out that, application of dry yeast as a foliar spray was found to increase growth, yield and quality of some vegetable crops. (Abdel Aziz 1997, Fathy and Farid 2000 on some vegetable crops, Abou El–Nasr et a.l, 2001 on squash, Fathy et al 2002 and Khedr and Farid 2002 on tomato plants, Tarek 2003 and Mona et al, 2005 on cucumber plant). Amino green compound contains (w/v) told organic acids plus amino acids 15% and some microelements such as iron, zinc and manganese. Micronutrients in yeast and amino green compound play a very important role in vital processes of plants. They improve photosynthesis which intensifies the assimilating activity of the whole plants (Marschner, 1995). Zinc in plants is involved in enzymatic relations. One of the most important functions of zinc shows that starch synthesis is widely interrupted at zinc deficiency. It was also added that zinc plays also an important role in protein synthesis from amino acids and in decarboxlation of pyruvate. Concerning iron, Derar et al., 1996 observed that using Received 19/9/2010 accepted 4/10/2010 Mesopotamia J. of Agric. (ISSN 1815 – 316X) Vol. (38) No. (Supplement 1) 2010 some materials containing Fe as a foliar spray significantly increased growth and yield of beans. Humic acid is particularly used to decrease the negative effects of chemical fertilizers and could have beneficial effect on the nutrition of the plant (Martinez et al., 1983). The commercial humic acids were found to improve growth, yield production, quality and increased significantly in the accumulation of P,K, Ca, Mg, Fe, Zn and Mn in tissues of some vegetable crops (David et al 1994, Padem and Ocal 1999 and Erik et al., 2000).This work was carried out to study the effect of dry yeast, amino green compound and humic acid as a foliar spray on the growth, yield and chemical contents of head lettuce plants. MATERIALS AND METHODS The present investigation was carried out during the two successive seasons of 2004/2005 and 2005/2006 at Berkash Giza Governorate, to study the effect of 7 treatmentsas a foliar application .i.e., dry yeast, amino green compound and humic acid at two rates for eash compared with the control (spray with water only) on growth, yield and chemical content of lettuce plants. Seeds of head lettuce (Lactuca sativa L.) cv. Lymar (9283) were drilled in foam trays of 209 holes in a media consisting of peatmoss and vermiculite 1:1. Trays were wetted and warmed under plastic sheet for three days, then kept under plastic tunnel. Normal nursery treatments were followed till seedlings become suitable for transplanting. The time of transplanting took place 15 and 19 th of November in both seasons, respectively. The seeds of head lettuce was cultivated in Mid. September in the two seasons of study. The experiment included seven treatments as follows: 1Foliar spray with water (control). 2Foliar spray with amino green compound at a rate of 2 ml/L.( Amino 1) 3Foliar spray with amino green compound at a rate of 4 ml/L.( Amino 2) . 4Foliar spray with dry yeast at a rate of 2 g/L.( Yeast 1). 5Foliar spray with dry yeast at a rate of 4 g/L. ( Yeast 2) 6Foliar spray with humic acid compound at a rate of 2 ml/L. (Humic 1) 7Foliar spray with humic acid compound at a rate of 4 ml/L. (Humic 2) Plants were sprayed with dry yeast, amino green compound and humic acid solution at 4 and 6 weeks after transplanting. Pest control and other agriculture practices, such as cultivation and irrigation, etc. were applied wherever it was necessary and as commonly recommended in the commercial head lettuce production. Harvesting was carried out 85 and 91 days after transplanting in the first and second seasons, respectively.With regard to the chemical analysis of the dry yeast, N.R.P 1977 stated that, the analysis of dry yeast was protein (47.2%), arginine (2.6%), glycin (2.6%), histidin (1.4%), islysine (2.9%), lauicine (3.5%), Lysine (3.8%), methionine systine (0.6%), phnyl-alanine (3%), tyrosine (2.1%), threonine (2.6%), tryptophan (0.5%) and vitamin B (2.9%). Goyal and Khuller (1992), Yatskovskaya et al (1992), Murakami et al (1996) Ahmed et al (1997) and Khedr and Farid (2002) reported that, yeast preparation contained carbohydrates, sugars, proteins, fatty acids, amino acids, hormones, macro and micro elements in suitable balance. Amino green compound contains (w/v) total organic acids plus amino acids 15%, iron (Fe) 2.9%, zinc (Zn) 1.4% and manganese (Mn) 0.7%, free amino acids, proline, hydroxy proline, glycine, alanine, valine, methionine, Mesopotamia J. of Agric. (ISSN 1815 – 316X) Vol. (38) No. (Supplement 1) 2010 escaliosin, lysine, cycteine, phenylalanine, serine, glutamic, arginine, histidine, lysine and hystiden.Humic acid compound contains humic acid 25.0 g/L, Folic acid 0.7 g/L, nitrogen 4.0 g/L, phosphorus 0.6 g/L and potassium 8.0 g/L. This compound from theorem will be reformed to as "humic acid" . The experiment was arranged in a complete randomized block design in four replicates. Six plants of each plot were chosen randomaly at 75 days after transplanting and the following data were recorded. AVegetative growth: 1Number of leaves/ plant. 2Dry weight of leaves/ plant (g). BYield: 1Average head weight (g) 2Total yield (Ton/fed.) CChemical content: Samples of heads were taken at harvesting time. Ascorbic acid (vitamin C mg/100) and Total soluble solids (T.S.S) were determined according to A.O.A.C (1984). Nitrate-N content in the fresh head lettuce leaves was determined using the method of Wooley et al., (1960). Samples of leaves were oven dried at 70°C then fine grounded and wet digested. Total nitrogen, phosphorus and potassium concentration in the tissues of plant leaves were determined according to the methods described by Jackson (1958) Troug and Mayer (1939) and Brown and Lilleland (1946), respectively. Some micro-elements, i.e. Fe, Zn and Mn were determined using Atomic Spectrophotometer (Phillips) according to Chapman and Pratt (1961). Data obtained were subjected to the statistical analysis according to the method of Gomez and Gomez (1984). RESULTS AND DISCUSSION Data in Table (1) show clearly that, using dry yeast, amino green and humic acid as a foliar spray on head lettuce plants increased vegetative growth characters compared with the control treatment except for dry weight of leaves in the second season of the study. The highest number of leaves was recorded by using 4 ml/L amino green in the two seasons. On the contrary, the lowest number of leaves was found in case of the control treatment. These findings were true in both seasons. These results may be due to the physiological roles of amino acids in the amino green which increased the metabolic processes rate, and in the same time it is cells that each micronutrient in the amino green compound has a role in improving plant growth. Zn directly involved in the synthesis of the in dole acetic acid (IAA). Mn is directly involved in the catalytic rates in plants being the enzyme activator on some respiratory enzymes and in reaction of nitrogen metabolism and photosynthesis (Marschner 1995). These results may be attributed to the effect of yeast extract in increasing levels of endogenous hormones in treated plants which could be interpreted by cell division and cell elongation (Khedr and Farid، 2002). In addition, these results may be due to the physiological roles of vitamins and amino acids in the yeast extract which increased the metabolic processes role and levels of indogenous hormones, i.e. IAA and GA3 (Chailakhyan، 1957). Mesopotamia J. of Agric. (ISSN 1815 – 316X) Vol. (38) No. (Supplement 1) 2010 Table(1): Effect of foliar spray of amino green, yeast and humic acid on leaf number and leaves dry weight of head lettuce plants in 2004-2005 and 2005-2006 seasons. 2005-2006 2004-2005 Treatments Leaves dry weight (g) Leaves Number Leaves dry weight (g) Leaves Number 21.83 33.02 14.73 36.30 Control 16.02 43.30 16.49 38.60 Amino 1 20.80 49.00 16.25 43.40 Amin