Machibya Masanja The aim of this study was to improves awareness on the effects of parthenium weed in different crops particulary in the maize and beans to the farmer in parts of Tanzania since Several studies reported on the distribution of parthenium weed as done by R .Kilewa in 2010 these study showed that parthenium is the major inversive weed in cropped and non cropped area , In Tanzania Parthenium weed firstly recorded in Arusha along the road side near Arusha airport and in Arusha city also near the Kilimanjaro international airport an ealier the country does not report the occurrence of the parthenium but noe day weed found in more than five region in Tanzania ,During the experimentation The randomized block design was used in which the four plots used with six treatments The first and the second plots will contain beans,maize and parthenium weed respectively while the third and the fourth plots will contains beans and maize with no parthenium weed respectively as the controller of the experiment ,then the data was collected and analysed as The crops in this plots grew well from the second week with the average height of 6.13cm to 16.1cm for maize crops as well as 4.3cm to 8.2 for the plots which contain beans only a in the second week ,this indicate that this plots were not affected with the weed in their growth as the growth well with no effect interfeared during their growth Also in the expermental plots The experimental plots was divided into two plots where by the first plots contained maize and parthenium and the rest plots contain beans and parthenium weed ,thus the average growth for the first plots was 5.97cm in the second week as well as 13.1cm in the 4th week and in the plots the average growth was 3.9cm for the second week as well as 7.7cm in the 4 th week of the experimentation. Thus the rate of growth was slow as compared to control plots due to chemical released by parhenium weed
1.O INTRODUCTION
1.1 Background information
The parthenium weed is the species of the flowering plants in the asteracea family which native to America tropics (Oudhia, 2000) the common name for this weed is called Santa Maria, famine weed , White top weed and weed carrot which is known in many part of Africa including Tanzania(R Kilewa 2017) .Moreover the germination of parthenium reach at maximum 1-6 cm tall after the aches ripen their seed un able to germinate in the soil below depth of 5cm and the whole cycle of the plants is completed within 5 moths thus after germination the young plants form a basal rossete of pale green which persist during unfarvourable time such as water or cold stress , as the stem elongates the leaves produced became rigid , angular which became stem and the soft trichomes of the leaves considered importance within the genus (Kohil and Ran, 1994)
The parthenium weed are native to North America(Bajwa et 2016) as reported about origin of parthenium weed also the weed introduced into Australia and India in the 150s as the probably as the contaminants of the grains or pasture weed , parthenium weed has archived weed status in those countries (MC Connachie et 2011) but now days the species present in Asia ,Africa ,North America ,Central America, South America , Europes and Oceania. In Tanzania the wees carrot were firstly reported in Arusha in 2010 thus since in this year the distribution of parthenium increased to many Other region apart from Arusha include Kagera and Mara region (Kilewa Ramadhan 2014) Thus parthenium weed is the invasive species which causes different effect on the distributed land for example farm land as the result lead to the loss of yields (Fite, 2017) since this plants produces alleloparthic chemicals like parthenin, ambrosin, and hysterin that suppress crops and pasture plants and allegies effects to human and livestock (Shabir, 2006) , ever since this weed became the problem (menace) around the globe including Africa effort have made to control such as mechanical , competitive replacement, chemical as where as biological control ((Adkins, 1976).Parthenium plant contains chemicals, like parthenin, hysterin, hymenin, and ambrosin, and due to the presence of these chemicals, the weed exerts strong allelopathic effects on different crops( (Tefera, 2002). Parthenin has been reported as a germination and radical growth inhibitor in a variety of dicot and monocot plants [13]. The weed affects nodulation in legumes due to inhibition of activity of nitrogen fixing and nitrifying bacteria, namely, Rhizobium, Actinomycetes, Azotobacter, and Azospirillum. Parthenium produces enormous numbers of pollens (on an average 624 million) (Wambura, 2018).
1.2 Problem statements
Since the parthenium weed is the invasive species which causes the effect of the distributed farm land for examples the farm land and pasture land as results causes the loss of yields to some crops like Wheat, Maize and Millets(Fite 2017) . Also the weed has been reported as the germination and radical growth inhibitors in variety of monocots and dicots plants as caused by parthenin chemicals which produced by the weed(Tefera 2002)
In Tanzania the parthenium weed still not be investigated on their effects to Maize and Beans thus through this study their effects on selected crops will be known .
1.3 Objective of the study
1.3.1 General objective
The investigation of the effects of parthenium weed on growth of different crops.
1.3.2 Specific objectives
To dertemine the effects of pathenium weed on the growth of selected Crops To compare the extents on the effects of parthenium between monocot and dicot crops .
1.4 Research question
How parthenium weed affect the growth of selected crops? In which extent monocot and dicots is affected by parthenium weed ?